/*
 * Copyright 2022 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkAvifCodec_DEFINED
#define SkAvifCodec_DEFINED

#include "include/codec/SkEncodedImageFormat.h"
#include "include/codec/SkEncodedOrigin.h"
#include "include/core/SkData.h"
#include "include/core/SkRefCnt.h"
#include "include/private/SkEncodedInfo.h"
#include "src/codec/SkFrameHolder.h"
#include "src/codec/SkScalingCodec.h"

#include <cstddef>
#include <memory>
#include <vector>

class SkCodec;
class SkStream;
struct SkImageInfo;
struct avifDecoder;
struct AvifDecoderDeleter {
    void operator () (avifDecoder *decoder) const;
};
using AvifDecoder = std::unique_ptr<avifDecoder, AvifDecoderDeleter>;

class SkAvifCodec : public SkScalingCodec {
public:
    /*
     * Returns true if an AVIF image is detected. Returns false otherwise.
     */
    static bool IsAvif(const void *, size_t);

    /*
     * Assumes IsAvif() was called and it returned true.
     */
    static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result *);

protected:
    Result onGetPixels(const SkImageInfo &dstInfo, void *dst, size_t dstRowBytes, const Options &options,
        int *rowsDecoded) override;

    SkEncodedImageFormat onGetEncodedFormat() const override
    {
        return SkEncodedImageFormat::kAVIF;
    }

    int onGetFrameCount() override;
    bool onGetFrameInfo(int, FrameInfo *) const override;
    int onGetRepetitionCount() override;
    const SkFrameHolder *getFrameHolder() const override
    {
        return &fFrameHolder;
    }

private:
    SkAvifCodec(SkEncodedInfo &&, std::unique_ptr<SkStream>, sk_sp<SkData>, AvifDecoder, SkEncodedOrigin, bool);

    // fAvifDecoder has a pointer to this data. This should not be freed until
    // the decode is completed. To ensure that, we declare this before
    // fAvifDecoder.
    sk_sp<SkData> fData;

    AvifDecoder fAvifDecoder;
    bool fUseAnimation;

    class Frame : public SkFrame {
    public:
        Frame(int i, SkEncodedInfo::Alpha alpha) : INHERITED(i), fReportedAlpha(alpha) {}

    protected:
        SkEncodedInfo::Alpha onReportedAlpha() const override
        {
            return fReportedAlpha;
        }

    private:
        const SkEncodedInfo::Alpha fReportedAlpha;

        using INHERITED = SkFrame;
    };

    class FrameHolder : public SkFrameHolder {
    public:
        ~FrameHolder() override {}
        void setScreenSize(int w, int h)
        {
            fScreenWidth = w;
            fScreenHeight = h;
        }
        Frame *appendNewFrame(bool hasAlpha);
        const Frame *frame(int i) const;
        int size() const
        {
            return static_cast<int>(fFrames.size());
        }
        void reserve(int size)
        {
            fFrames.reserve(size);
        }

    protected:
        const SkFrame *onGetFrame(int i) const override;

    private:
        std::vector<Frame> fFrames;
    };

    FrameHolder fFrameHolder;
    using INHERITED = SkScalingCodec;
};

#endif // SkAvifCodec_DEFINED
